Input System

Keyboards, mice, gamepads, touchscreens — your players have a lot of ways to interact with your game. UE5's Enhanced Input System gives you a clean, flexible way to handle all of them by separating the what (the action) from the how (the key binding).

Core Concepts

Input Actions

An Input Action (IA) represents what the player wants to do — jump, fire, move, interact. It doesn't care which button triggers it. Think of it as the intent. Input Actions also define the value type they produce: a bool (pressed/released), a float (trigger pressure), or a Vector2D (thumbstick direction).

Create one by right-clicking in the Content Browser: Input > Input Action.

Input Mapping Contexts

An Input Mapping Context (IMC) maps physical inputs (keys, buttons, sticks) to Input Actions. "Spacebar triggers Jump." "Left stick triggers Move." You can swap mapping contexts at runtime — different controls for driving vs walking vs menus.

Create one by right-clicking in the Content Browser: Input > Input Mapping Context.

Modifiers and Triggers

Modifiers transform the raw input (dead zones, sensitivity curves, axis negation). Triggers define when the action fires (pressed, released, held for a duration).

Setting It Up in HELIX Studio

1. Right-click in the Content Browser > Input > Input Action — create actions like IA_Jump, IA_Interact
2. Right-click > Input > Input Mapping Context — create IMC_Default
3. Open your mapping context, add your actions, and bind keys to them
4. In your Player Controller or Character, add the mapping context at BeginPlay

Binding a Key Press

Blueprint

Blueprint— Enhanced Input — Jump

Lua

-- Bind an enhanced input action
function MyCharacter:SetupPlayerInputComponent(InputComponent)
    local EIC = InputComponent:Cast(UE.UEnhancedInputComponent)
    EIC:BindAction(self.JumpAction, UE.ETriggerEvent.Triggered, self, self.HandleJump)
end

function MyCharacter:HandleJump()
    self:Jump()
end

JavaScript

class MyCharacter extends ue.Character {
    SetupPlayerInputComponent(inputComponent) {
        let eic = ue.EnhancedInputComponent.Cast(inputComponent);
        eic.BindAction(this.JumpAction, ue.ETriggerEvent.Triggered, this, "HandleJump");
    }

    HandleJump() {
        this.Jump();
    }
}

Supported Devices

The Enhanced Input System handles all common devices out of the box:

• Keyboard & Mouse — individual key bindings, mouse axes, scroll wheel
• Gamepad — buttons, triggers with analog pressure, thumbsticks
• Touch — tap, swipe, and multi-touch gestures

You can bind the same Input Action to multiple devices in your mapping context, so players can use whatever controller they prefer without any extra code on your end.

Why Enhanced Input?

The older input system (Action Mappings / Axis Mappings) still works but is deprecated. Enhanced Input gives you:

• Runtime remapping — let players rebind keys without restarting
• Context switching — swap entire control schemes on the fly
• Modifiers — dead zones, sensitivity, and input smoothing built in
• Multiplayer-friendly — each player can have their own mapping context

HELIX Input API (Lua)

In addition to UE5's Enhanced Input System, HELIX provides a simpler Input class for quick key binding in Lua scripts:

-- Bind a key press
Input.BindKey('Tab', function()
    print('Tab Pressed')
end, 'Pressed')

-- Bind a key release
Input.BindKey('Tab', function()
    print('Tab Released')
end, 'Released')

The Input.BindKey function takes a key name (string), a callback function, and an optional listener type ('Pressed' or 'Released'). This is useful for quick prototyping and UI interactions without setting up full Input Actions.

tip

Name your Input Actions with an IA_ prefix and Mapping Contexts with IMC_. Your Content Browser will thank you when you have dozens of them.